Salla Disease

Reports from the MHC data base

Synonyms

Sialic acid storage disorder

SIASD

Sialuria Finnish type

Codes:

ICD-10: E77.8ORPHA: 309334

Estimated occurrence

4:1 000 000 inhabitants

Etiology

Defect on the SLC17A5-gene on chromosome 6. The disease is inherited autosomal recessively. The transport of sialic acid from the lysosomes of the cells does not function as it should. Sialic acid thus accumulates in the cells and a greater amount is excreted in the urine. The disease implies that the myelin sheaths around the axons in the brain develop poorly. This probably causes impulses to propagate more slowly along the axon and results in neurological and motor symptoms.

General symptoms

Symtoms appear during the first year of infancy as delayed motor development and low muscle tone (hypotonia). The children have difficulty in coordinating movement and maintaining balance (ataxia), and some present involuntary movements (athetosis) and/or intense reflexes in the legs (spasticity). Most individuals with Salla disease have severe intellectual disability. Some have epileptic seizures during adolescence, usually in the form of absence seizures. Spasticity in the legs and arms increases with age, motor activity deteriorates and some lose the ability to walk.

Orofacial/odontological symptoms

Neurological impairment affects oral motor and speech development and difficulties with eating and drooling are common. Frontal open bite is a frequent finding.

Orofacial/odontological treatment

Early contact with dental services for intensified prophylactic care and oral hygiene information is essential.

Regular check-ups of dental and jaw development. Orthodontist should be consulted when needed.

Speech, language and communication training are often required.

Training in oral motor skills and extra stimulation in cases of eating disorders, speech difficulties and drooling may be relevant.

Sources

The rare disease database of the Swedish National Board of Health and Welfare.

The MHC database - The Mun-H-Center database on oral health and orofacial function in rare diseases.

The Documentation from the Ågrenska national competence centre for rare diseases.